diff --git a/chatter/chatterbot/conversation.py b/chatter/chatterbot/conversation.py
index c9dfcb4..1926420 100644
--- a/chatter/chatterbot/conversation.py
+++ b/chatter/chatterbot/conversation.py
@@ -3,6 +3,7 @@ class StatementMixin(object):
     This class has shared methods used to
     normalize different statement models.
     """
+    tags = []
 
     def get_tags(self):
         """
diff --git a/chatter/chatterbot/parsing.py b/chatter/chatterbot/parsing.py
index d7ad4d2..5aafa75 100644
--- a/chatter/chatterbot/parsing.py
+++ b/chatter/chatterbot/parsing.py
@@ -611,6 +611,7 @@ def date_from_duration(base_date, number_as_string, unit, duration, base_time=No
     if base_time is not None:
         base_date = date_from_adverb(base_date, base_time)
     num = convert_string_to_number(number_as_string)
+    args = {}
     if unit in day_variations:
         args = {'days': num}
     elif unit in minute_variations: